Christensen Søren T, Voss Jesper W, Teilmann Stefan C, Lambert Ian H
Institute of Molecular Biology and Physiology, The August Krogh Building, Department of Biochemistry, University of Copenhagen, Universitetsparken 13, DK-2100 Copenhagen OE, Denmark.
Cell Biol Int. 2005 May;29(5):347-51. doi: 10.1016/j.cellbi.2005.02.003.
Taurine, present in high concentrations in various mammalian cells, is essential for regulation of cell volume, cellular oxidative status as well as the cellular Ca2+ homeostasis. Cellular taurine content is a balance between active uptake through the saturable, Na(+)-dependent taurine transporter TauT, and passive release via a volume-sensitive leak pathway. Here we demonstrate that: (i) TauT localizes to the primary cilium of growth-arrested NIH3T3 fibroblasts, (ii) long-term exposure to TNF(alpha) or hypertonic sucrose medium, i.e., growth medium supplemented with 100 mM sucrose, increases ciliary TauT expression and (iii) long-term exposure to hypertonic taurine medium, i.e., growth medium supplemented with 100 mM taurine, reduces ciliary TauT expression. These results point to an important role of taurine in the regulation of physiological processes located to the primary cilium.
牛磺酸在各种哺乳动物细胞中含量很高，对调节细胞体积、细胞氧化状态以及细胞内钙离子稳态至关重要。细胞内牛磺酸含量是通过可饱和的、依赖钠离子的牛磺酸转运体TauT进行主动摄取与通过容积敏感性渗漏途径进行被动释放之间的平衡。在此我们证明：（i）TauT定位于生长停滞的NIH3T3成纤维细胞的初级纤毛；（ii）长期暴露于肿瘤坏死因子α（TNFα）或高渗蔗糖培养基（即添加100 mM蔗糖的生长培养基）会增加纤毛TauT的表达；（iii）长期暴露于高渗牛磺酸培养基（即添加100 mM牛磺酸的生长培养基）会降低纤毛TauT的表达。这些结果表明牛磺酸在调节位于初级纤毛的生理过程中具有重要作用。
